How to use Values after retrieving data with firebase in swift? - ios

Question

so far I have always worked with the data i am retrieving from firebase without having to do something with them besides showing.
Now I would actually need to store the data in another array and/ or also in general I really wonder how to actually work with the data.
My approach right now looks like this but its actually not working.
Does anyone know how to do it?
....
class ProjectCharacterViewController: UIViewController {
// MARK: - Properties
var soloJobs: [String] = []
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
getJobs(for: User.current) { (memberJob) in
self.uniqueJobs = memberJob
}
}
...
func getJobs(for user: User, completion: #escaping ([MemberJobsStruct]) -> Void) {
var jobs: [String] = []
let ref = Database.database().reference().child("team").child(user.uid)
ref.observe(DataEventType.value, with: { snapshot in
for case let child as DataSnapshot in snapshot.children {
guard let value = child.value as? [String: Any] else {
return completion ([])
}
let memberJob = value["memberJob"] as! String
jobs.append(memberJob)
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
})
soloJobs = jobs
}

Answer 1

Since the observe function is an asynchronous call, your soloJobs = jobs is getting called before it. That is why it is returning an empty array, because, at that time, your jobs array is also empty. Consider calling it inside your for loop as so:
func getJobs(for user: User, completion: #escaping ([MemberJobsStruct]) -> Void) {
var jobs: [String] = []
let ref = Database.database().reference().child("team").child(user.uid)
ref.observe(DataEventType.value, with: { snapshot in
for case let child as DataSnapshot in snapshot.children {
guard let value = child.value as? [String: Any] else {
return completion ([])
}
let memberJob = value["memberJob"] as! String
jobs.append(memberJob)
self.soloJobs = jobs
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
})
}